1. Field of the Invention
The present invention relates to a sheet aligning apparatus and a processing apparatus, and more particularly relates to a sheet aligning apparatus and a processing apparatus used for a copying machine capable of processing a plurality of jobs successively.
2. Description of the Related Art
A copying machine having a multi-job function has been known. The multi-job function refers to a function of processing two groups of original documents successively by setting the two groups of originals (a group of originals for a first job and a group of originals for a second job) at an automatic document feeder (hereinafter referred to as "ADF") of the copying machine.
In addition, an aligning function is provided for matching the positions of the copied sheets if there produced a plurality of copied sheets in such a copying machine. When the copied sheet for the first job and the one for the second job discharged onto the same tray are different in size, the aligning function does not work.
The multi-job is also applied when the number of original sheets to be set at ADF exceeds the loading capacity of the tray of ADF. The originals are divided into those for the first job and those for the second job to be set by an user, allowing consecutive processing of the originals.
Japanese Patent Laid-Open No. 56-54455 discloses a technique of controlling a job by reading out information using ADF concerning the job written by an user on a sheet.
These copying machines exhibit a problem of poor operability. Specific problems are given below.
(1) First problem
In the conventional copying machine, if the sizes of the copied sheets are different between the first job and the second job, the copied sheets are not aligned since the aligning function does not work.
In order to solve this problem, copy operation for the second job may be suspended until aligned sheets for the first job are removed.
However, this process could lower working efficiency.
(2) Second problem
There is a copying machine having a function of post-processing the sheets after copying. The post-processing refers to a process such as stapling of the discharged sheets which have been aligned.
A problem of such a copying machine is that even if one group of originals are divided into a plurality of groups for a plurality of jobs to be set, the copying machine cannot recognize the state in which the group of originals is divided, so that the divided groups of originals are post-processed separately.
(3) Third problem
According to the conventional multi-job control, when the process for the second job is carried out in succession after completion of the first job, the total of the sheets to be processed often exceeds the amount that the copying machine can process. For example, setting of the number of sheets to be copied could exceed limitations of the number of copies because of the limitations of the number of bins of the sorter.
If all the bins of the sorter are utilized for sorting operation in the first job, the sorting operation is impossible for the second job. However, the copying machine cannot recognize such a state.
The invention is made to solve the problems described above. The first object of the invention is to enhance operability of an image forming apparatus (e.g. copying machine) capable of executing a plurality of jobs successively.
The second object of the invention is to provide a sheet aligning apparatus capable of aligning sheets of different sizes appropriately.
The third object of the invention is to provide a sheet aligning apparatus capable of precisely carrying out post-processing even if one group of original documents is divided into those for a plurality of jobs.
The fourth object of the invention is to provide a processing apparatus capable of suitably carrying out processes in an image forming apparatus which can process a plurality of jobs successively.